Method for managing assembling process of electrical product

Abstract

A method for managing an assembling process of an electrical product. The electrical product at least includes a substrate with a semiconductor component mounted thereon and a power supply circuit. In the method, during assembly of the electrical product, a potential difference between two points on electric wires or signal wires electrically connected with an impedance element, which is inside the electrical product, interposed therebetween is constantly measured. Also, in the method, if a change that exceeds a predetermined threshold value, based on which electrostatic discharge noise and a normal potential range are distinguished from each other, occurs in the potential difference between the two points, measurement data on the potential difference between the two points is recorded and a mark for indicating that the electrical product was affected by electrostatic discharge is provided to the electrical product.

The invention claimed is: 
     
       1. A method for managing an assembling process of an electrical product, the electrical product including a power supply circuit and a substrate on which a semiconductor component is mounted, wherein the power supply circuit supplies a potential across the semiconductor component, the method comprising:
 electrically connecting two lines of a static electricity measuring equipment to two points on electrical lines or signal lines electrically connected across the semiconductor component; 
 continuously measuring a potential difference between the two points on the electrical lines or the signal lines electrically connected across the semiconductor component inside the electrical product throughout the assembling process of the electrical product; and 
 when a change in the potential difference measured between the two points on the electrical lines or the signal lines exceeds a predetermined threshold for distinguishing between static electricity discharge noise and a normal potential range occurs during the assembling process of the electrical product, measurement data of the potential difference between the two points is recorded in a computer in communication with the static electricity measuring equipment and a marker is provided in the measurement data of the potential difference between the two points for identifying that the electrical product is affected by static electricity discharge to the electrical product. 
 
     
     
       2. The method for managing the assembling process of the electrical product according to  claim 1 ,
 wherein, as the potential difference between the two points, a potential difference between two electrical lines which connect the power supply circuit and the semiconductor component is measured. 
 
     
     
       3. The method for managing the assembling process of the electrical product according to  claim 1 , wherein connectors for measuring the potential difference are prepared in advance at the two points on the electrical lines or the signal lines which are measurement points. 
     
     
       4. The method for managing the assembling process of the electrical product according to  claim 1 , wherein the potential difference between the two points on the signal lines is measured by utilizing connectors for a signal test provided on the signal lines. 
     
     
       5. The method for managing the assembling process of the electrical product according to  claim 1 ,
 wherein, as the potential difference between the two points, a potential difference between terminals of a plug of the power supply circuit is measured. 
 
     
     
       6. The method for managing the assembling process of the electrical product according to  claim 1 ,
 wherein the potential difference between the two points is measured at a measurement period of equal to or less than 100 ns. 
 
     
     
       7. The method for managing the assembling process of the electrical product according to  claim 1 , wherein the static electricity measuring equipment which measures the potential difference between the two points is wirelessly connected to the computer which records measurement data of the potential difference between the two points.